Hydraulic press



W. P. MUIR HYDRAULIC PRESS Feb. 13, 1951 4 Sheets-Sheet 2 Filed Jan. 25,1947 mu v2 3 m@ \u w 5w m u -T x T mo 3 i 1 ow E W W M I 2K m 0.2L 1 1+u NOM\OI1J m m HNVENTQ \MEQMUJIR ATTORNEYS W. P- MUIR HYDRAULIC PRESSFeb. 13,1951

4 Sheets-Sheet 3 Filed Jan. 25, 1947 /9 INVENTOR W.P MUIR WW2? kgATTORNEYS W. P. MUIR HYDRAULIC PRESS Feb. 13, 1951 4 Sheets-Sheet 4Filed Jan. 25, 1947 INVENTOR WPMUIR ATTORNEYS? Patented Feb. 13, 1951HYDRAULIC PRESS William P.. Muir, Hampstead, Quebec, Canada,

assignor. to Dominion Engineering. Works Limited, Lachine, Quebec,Canada Application January'25, 1947, SerialNo. 724,424

6 Claims. 1

This invention relates to hydraulic presses and particularly to verticaldraw-presses in which the work is subjected to a long or deep draw" bymeans of aring draw-die and a cooperatingpunch.

In vertical draw-presses of conventional design, the punch is rigidlysecured to a ram-operated cross-head so that it is always disposed in avertical position in line withthe opening of a ring draw-die carried bya stationary dieholder rigidly mounted on-the press base. These pressesare frequently used for re-drawing operations in which a piece ofpreviously drawn work with a solid end is redrawn to increase its lengthand decrease its diameter and, wall thickness; Such presses are designedto come to rest with the lower end of the punch positioned above the diea distance greater than the length of the work to be redrawn in order toenable the Work tobe placed on the die and held in a vertical positionto receive the punch as the latter travels downwardly on its workingstroke. This means that the press daylightf theheight, and the-idleadvance or' pre-fill' stroke of the press must be increased beyondreasonable proportions in order to provide for the redrawing ofpreviously drawn work of considerable length. The" excessive increase inthe press daylight and height of the press is undesirable in that itinvolves an excessive increase in the head room required forinstallation of the press and gives rise to excessive vibration. Theaccompanying increase in the length of the idle advance or; pre-fillportion of the punch stroke slows down the working cycle of the press toa very substantial degree.

Press daylight is the term applied to the maximum distance between thetop face of the press base and the underface of the movablepunch-carrying crosshead when the crosshead is at the limit of itsupward travel. This distance is the summation of certain dimensionssuch. as the length of the die holder, the length of the work, thelength of the punch, the length of the punch holder by means of whichthe punch is attached to the crosshead, and certain clearancedimensions. In a conventional draw-press designed fora long draw thepress daylight adds up to a large dimension out of all proportion withthe other dimensions'of the press and requiring excessive headroom. Theidle advance orpre- I fill portion of the working strokeof the punch isincreased, with resulting slowing down of the working cycle, asthe-clearance between the draw die and the retracted punch is increasedto take care of an increase in the'length of the work.

' punch is tiltable from a Verticalworking position in axial alignmentwith, the draw-die. to. an inclined leading position in which. the lowerend of the punch is. displaced to one side of thedraw die and die holderto permit the work; to. be slipped upwardly onto the punch, which isthen tilted backto its vertical position to. center the work withreference to the ring draw diethrough which the work is forced by thepunch, during the downward or working stroke of the punchcarryingcrosshead.

The punch i tilted from its vertical working position to its inclinedloading position and viceversa by suitable tilting mechanism which maybe automatically or manually controlled. The tiltingmechanism maycomprise a cylinder and piston device or other punch tilting meansoperable toswing the punch about a pivoted axis and preferably includescontrol means: interlocked with other control elements of the press tomake it impossible to effect a working stroke. of the press unless thepunch is in its vertical working position.

The inclined loading of the work. onto the punch may be accomplished byhand but, for convenience, rapidity, and safety, is preferablyaccomplished by'a power-operated manually controlled loading mechanismwhich functions to slide the workonto the punch and to then actuate acontrol element which causes the punch tilting mechanism to swing thepunch and the work to a. vertical position. in operative alignment withthe opening, of the draw die. through which the work is forced by asubsequent downward working stroke of the punch.

The press is also preferably equipped with automatic control meanswhereby the punch. tilting mechanism is operated to automatically tiltthe punch from its vertical working position to its inclined loadingposition as the punch-carrying crosshead reaches the limit of its upwardreturnstroke travel.

Other characteristic features and advantages of the invention will beapparent irom the following detailed description of the accompanyindrawings, in which Figure 1 is a view showing the conventional toolingarrangement of a hydraulic draw press of a type to which the presentinvention relates.

Figure 2 is a view similar to Figure 1 but showing an improved toolingarrangement embodying the essential features of'my invention.

Figure 3 is a diagrammatic view of a complete fluid circuit includingthe improved tooling arrangement and parts co-operating therewith.

Figure 4 is an enlarged view partly in side elevation and partly invertical section of my improved tooling arrangement.

Figure 5 is a side elevational view of the arrangement shown in Figure4.

Figure 6 is an enlarged detailed view of the punch-tilting mechanismshown in the preceding figures.

As shown in Fig. 1, the tooling arrangement of a conventional, vertical,hydraulic draw-press comprises a movable ram-operated crosshead 5 towhich a punch 6 is rigidly secured in vertical position by means of afixed punch holder 1. The punch 6 is centered with respect to thecentral opening of a ring draw die 8 fitted in the upper end of astationary die holder 9 rigidly mounted on the punch base It. The punch6 is shown at the limit of its upward travel and a work-piece II isshown interposed between the lower end of the punch and the draw die 8.The work piece I I is shown as a drawn tubular member having a solidlower end Ha against which the punch acts to force the work-piecedownwardly through the draw die to thereby increase the length anddecrease the diameter and wall thickness of the work-piece asrepresented, for example, by the redrawn work-piece l2 appearingdirectly below the draw die. The press stroke is indicated by thedistance line A while the press daylight is indicated by the distanceline B.

By virtue of the improved tooling arrange- 'ment shown in Fig. 2, thepresent invention substantially reduces the press daylight and thelength of the idle advance portion of the working stroke of the punch 6as will be seen by comparing the length of the press daylight distanceline B (Fig. 2) with the length of distance line B (Fig. 1). assemblingpunch 6' with crosshead 5' so that,

in the fully raised or retracted position of the crosshead, the punch istilted from the vertical working position shown in full lines to theinclined loading position indicated by dotted lines. In the inclinedloading position of the punch the lower end thereof is displaced to oneside of the draw die 8' and die holder 9 so that work-piece Il may beslid upwardly onto the punch which is then swung to its verticalposition to center .the work on the draw die prior to commence- .ment ofthe working stroke during which the descending punch forces the workdownwardly through the draw die to produce the finished drawn work l2shown beneath the draw die. This pivotal mounting of the punch so thatits lower end may be swung to a loading position at one side of the dieholder makes it feasible to reduce the press daylight so that, in thefully raised position of crosshead 5, the lower end of the punch iselevated above the draw die a relatively short distance which may beconsiderably less than the length of work-piece H. It will also be seenthat, with the work-piece fitted on the punch and the latter disposed inThis is accomplished by its vertical position, the punch makes only arelatively short idle advance before contacting the solid lower end ofthe work-piece and commencing the draw. This, obviously, speeds up theworking cycle as compared with the arrangement shown in Fig. 1 in whichthe length of the idle advance portion of the working stroke of thepunch is greater. than'the length of the workpiece [0.

The mounting of the tiltable punch The upper end of punch 6' (see Figs.3 to 6 inclusive) is screwed into a pivotally mounted punch holder I5.This holder is provided with trunnions l6 journalled in slide bearingsl'i fitted in guideways l 8 provided in a punch holder frame l9 rigidlysecured to the underface of crosshead 5'. The bearings H are free tohave a limited vertical movement in guideways l8 and are retainedtherein by bearing plates 20. The punch holder frame I9 is secured tocrosshead 5 by stud bolts l9a and nuts i912 so that it may be properlycentered by centering screws 25 bearing against the sides of said frameand having screwthreaded engagement with centering posts 22 carried bythe crosshead. This enables the punch 6' to be accurately located withreference to the cooperating draw die.

The punch holder i5 is formed witha convexly curved upper surface [5aadapted to bear against a concavely curved bottom floating bearingsurface 23 of a bearing block 24 fitted in punch holder frame I9.Bearing block 24 is also formed with a convexly curved upper bearingsurface 25 adapted to bear against a concavely curved bottom bearingsurface 26 of a thrust block 21 which is also fitted in frame [9 and isprovided with a flat upper surface for contact with the lower surface ofcrosshead 5. The curved bearing sur-. faces 15a, 23, 25 and 26 arearranged to permit self alignment of the punch 6 and punch holder 15 bymovement thereof in different paths at right angles to each other. Inthis connection it may be explained that the direction of curvature ofthe engaging bearing surfaces I50. and 23 of punch holder [5 andfloating bearing block 2 is at right angles to the direction ofcurvature of the engaging bearing surfaces 25 and 2G of bearing block 24and thrust block 2?. It may also be noted here that the self-aligningmovement of the punch occurs when the latter is under load and thetrunnion slide bearings I? are raised clear of their retaining plates 29so that the upward thrust of the punch is taken by the curved bearingsurfaces of the punch holder I5, floating bearing block 2 3, and thrustblock 21.

When punch 6' is placed under load, the bearings I! move upwardly in theguideways l8 so that the thrust, instead of being taken by saidbearings, is transmitted directly to the crosshead 5 through punchholder l5, bearing block 24 and thrust block 21.

The punch tilting mechanism Punch 6' is tilted from its vertical workingposition to its inclined loading position and viceversa by tiltingmechanism comprising tilting lever 29 having one end rigidly secured topunch holder 15 and the other end pivotally secured, by clevis 3|], tothe piston rod 3! of a piston 360. (Fig. 3) working in cylinder 32 whichis mounted on crosshead 5 by bearing bracket 33.

Cylinder 32 is connected in an air circuit, hereinafter described, sothat when crosshead 5 reaches the upper limit of its travel air issupplied. to the upper end and exhausted; from the lower end of saidcylinder to cause. the piston working therein to travel downwardly andthereby tilt the lever 29 and punch holder [5 to swine punch 6 from itsvertical Working position to its inclined loading position.

After the work I! has been loaded onto the inclined punch 6', therouting of air to and from cylinder 32 is reversed, as hereinafterexplained, so that air is exhausted from the upper end and supplied tothe lower end of said cylinder to effect upward movement of pistonoperating therein to thereby swing the punch 6' to its vertical workingposition. Following this, fluid is supplied to the working cylinder ofthe press to effect a downward or working stroke of the ram to whichcrosshead 5' is attached. Thepunch, descending with the crosshead,forces the work down.- wardly through the draw die.

An adjustable stop screw 34 is threaded upwardly through a stop bracket35 fastened to a side of punch holder [5 directly opposite the side towhich tilting lever 29 is attached. This stop screw is engageable with acooperating stop 36 of punch holder frame I9 to limit tilting movementof the punch holder and punch in one direction. Hardened stop plugs 3'!are fitted in punch holder frame 19 and tilting lever 23 to limitswinging movement of the punch holder and punch in the oppositedirection. An adiusting screw 39a is threaded upwardly through lever 29to provide for adjustment of the stop plug El carried by said lever.

A switch trip lever 38 is fixed to one of the trunnions it of punchholder I5 and functions to close a valve-controlling micro switch 39when the punch 6' is tilted to its vertical working position. Switch 39is supported by switch bracket is attached to crosshead 5' and opensautomatically when punch 6 is tilted to its inclined work receivingposition.

The work loading mechlanism The loading of work I l onto punch 6 may beaccomplished by hand but is preferably accomplished by a manuallycontrolled, power actuated, work loading mechanism generally indicatedat 4|. This mechanism comprises a loading head 42 arranged to slidealong an inclined loading bracket 43 provided with guides 43 betweenwhich the loading head is positioned. The loading bracket 43 is carriedby die holder 9 and the surface over which the loading head travels isinclined so that the loading head is in axial alignment with punch 6'when the latter is in its inclined loading position. The loading head 62is screwed onto the upper end of a piston. rod 35 having its lower endfastened to a piston 46 (Fig. 3) working in a loading cylinder 4"?mounted on the inclined loading head supporting surface of loadingbracket 43.

When the press is at rest with punch 6" in its inclined loadingposition, the piston operating in loading cylinder 5? is at the lowerend ofv said cylinder and the loading head 52 is in the loweredposition. as shownin Figs. 2 and 3. The work. i l is then placed onloading head 62' so that it is supported by the inclined guiding surfaceof loading bracket 43. Air is then supplied, as hereinafter described,to the lower end of loading cylinder t! to raise the loading piston andthe loading head 32 to thereby slide the work i l upwardly onto theinclined punch 6-. As the loading head :22 reaches the. upper limit of.its. travel fluid connections are established" whereby air is supplied 6to the lower end and exhausted from the upper end of punch tiltingcylinder 32 to cause the piston working therein to travel upwardly andthereby tilt the lever 29 and punch holder to swing punch 6 to itsvertical working position.

The air circuit This circuit (Fig. 3) includes a main air supply line 60connected to a pump or other suitable source of compressed air. Fromthis supply line air is routed to punch tilting cylinder 32 through line6!, four-way pilot-controlled reversing valve 62, telescopic line 63,connected to the upper end of said cylinder and telescopic line 64connected to the lower end of said cylinder.

Air is supplied to the lower end of punch-tilting cylinder 32 throughline 64 and exhausted from the upper end of said cylinder through line63 when reversing valve $2 is shifted to the right by pilot air pressuresupplied through pilot line 65, automatic loading-head actuated pilotvalve 66, and pilot line 61. Air is supplied to the upper end ofcylinder 32 through line 63 and is exhausted from the lower end of saidcylinder through line 64 when reversing valve 62 is shifted to the leftby pilot air pressure supplied through pilot line 68-, automaticcrosshead actuated pilot valve 6% and pilot line 10. The loading-headactuated pilot valve 66 is opened by a roller cam i! (Fig. 5) on loadinghead 12 when the latter reaches the limit of its upward travel duringthe loading of the work onto the punch 6. The crosshead-actuated pilotvalve 69 is opened by a cam 12 on crosshead 5 when the crosshead is atthe top of its stroke.

Air is routed to loading cylinder 4? from supply line 613 through line14, four-way pilot controlled reversing valve 15, line 16 connected tothe lower end of cylinder 41 and line 11 connected to the upper end ofsaid cylinder.

Air is supplied to the lower end of loading cylinder t1 through line itand exhausted from the upper end of said cylinder through line Ti whenreversing valve i5 is. shifted to the left by pilot air pressuresupplied from line 63 through pilot lines it and 88', manually operableload buttons 8| and 82 and pilot line 83. Air is supplied to the upperend of loading cylinder 11 through line H and exhausted from the lowerend of said cylinder through line it when reversing valve '55 is shiftedto the right by pilot air pressure. sup plied from line M through pilotline 85,. automatic cross-head actuated pilot valve 86, and pilot lines8? and The cross-head actuated pilotv valve 86 is opened by the;cross-head cam 12' when the cross-head has descended a short distance onits working stroke.

Two manually operable load buttons 84 and 82 are provided as a safetymeasure to compel the operator to use both hands in operating theloading mechanism and thus ensure that the operators two hands will besafely out of the way. The line connection between buttons 55 and. 82includes a bleed which prevents locked up air permitting the secondbutton alone to start the cycle.

The stroking of the press is controlled by a main. reversibie workingvalve, not shown, operating in a valve casing 69. This working valve isconnected by valve stem 95!, to an operating piston in working incylinder 92. Air is routed to cylinder-'33 from supply line 5c through.line line. 9% connected to the upper end of cylinder 93 and line 9!connected to the lower end of said cylinder.

Air is supplied to the upper end of the working valve operating cylinder92 through line 96 and is exhausted from the lower end of said cylinderthrough line 9'! when valve 95 is shifted to the right by pilot airpressure supplied from line 60 through pilot line 99,solenoid-controlled valve I60, pilot line 69!, non-repeat three-wayvalve H32, pilot line !03, manually operable start button m4, and pilotline N35. The operating solenoid its of valve I89 is connected to a Hvolt source ID? of electrical energy through the previously mentionedmicro switch 39 which is opened by trip lever 38 when the punch istilted to its loading position and closes automatically when the punchis swung back to its vertical working position.

Air is supplied to the lower end of working valve operating cylinder 92through line 9'! and is exhausted from the upper end of said cylinderthrough line 96 when reversing valve 95 is shifted to the left by pilotair pressure supplied through pilot line 429, automatic pressureoperated valve H0, and pilot lines HI and H2. Valve H0 is a normallyclosed valve which is opened auto-- matically b suitable distance tripmeans (not shown) when the punch has travelled a predetermined di tancein the working stroke direction.

An air vessel H5 connected to the air supply line 6!] through checkvalve I IE to provide a supplementary source of compressed air foroperating the main working valve of the press in event of failure of thenormal air supply.

The previously mentioned pilot line 19 is connected to one end of acylinder H8 containing a working valve locking piston H9. A piston rodl2!) is connected to piston H9 and is provided at its free end with alatch lZi which engages at times in a notch 90a provided inworking-valve stem 9%. Piston H8 is operated to a working valve lockingposition by air pressure supplied to cylinder E E8 through pilot line 19and is operated to a working valve releasing position by its biasingspring i22 when line 19 is connected to exhaust through the reversingvalve 52 controlling the punch tilting piston 3 l.

A pilot line E24 is connected between the pilot line 83 serving thereversing valve of loading cylinder ll and the pilot lines Ill and H2serving the reversing valve 95 of the working valve operating cylinder92.

The pilot line H serving the reversing valve 95 of working-valveoperating cylinder 92 is connected, through a normally closed automaticstarter valve I26 and pilot line l2! to non-repeat valve H12.

Operation of air circuit and parts associated therewith As previouslystated, the press comes to rest with the punch 6 in its inclined loadingposition and the loading head 42 in its lowered position. The operatorplaces the work on the loading head 32 and then presses the two loadingbuttons 8| and 82 to open position. Since reversing valve 62 is nowpositioned to supply air through lin 63 to the upper end of cylinder 32to hold punch 6 in its inclined loading position, it will be seen thatthe opening of buttons 81 and 82 results in pilot air pressure beingsupplied to the right hand end of reversing valve 15 through pilot linesI9 and 80, buttons BI and 82, and pilot line 83,

thereby reversing valve 15 to supply air to the lower end of loadingcylinder 41 through pipe 16 and to exhaust air from the lower end ofsaid loading cylinder through pipe 11. The resulting upward movement ofloading piston 46 and loading head 42 causes the work I l to be slidupwardly onto the punch 6.

As the loading head 42 reaches the upper limit of its travel, it'openspilot valve 65 so that pilot air pressure is supplied through pilot line65,

pilot vave 66, and pilot line 61 to the left hand end of reversing valve62, which is thus shifted to the right to supply air to the lower end ofpunch-tilting cylinder 33 through line 64' and to exhaust air from theupper end of said cylinder through line 63, thereby operating piston 3|in an upward direction to swing punch 6 to its vertical operatingposition in line with drawring 8.

As punch 6' swings to its vertical operating position, the switch triplever 38 moves against switch 39, thereby closing the latter to energizesolenoid I96 and open valve N30 to supply operating air tomanually-operable start button IM through line I93 and to automaticstart valve I26 through line E21.

If the automatic start valve I26 is open, air will be delivered throughthis valve and the pilot line I05 to the left hand end of reversingvalve 95 and will operate the latter to supply air to the upper end ofcylinder 92 through line 95 and to exhaust air from the lower end ofsaid cylinder through line 9?. The resulting downward movement of piston9| will lower the working valve in valve casing 89 to a positionestablishing fluid connections through which hydraulic pressure fluid isrouted to and from the press ram to ellect a downward working stroke ofthe punch carrying crosshead 5. If the automatic start valve :26 isclosed when solenoid-actuated valve EHO is opened by closure of switch39, the manually operable start button I04 is opened to reverse valve 95and effect a Working stroke of the press. When crosshead 5' hasdescended a short distance on its working stroke, the cross head cam 12opens pilot valve through which air pressure is delivered to operatereversing valve 15 to a position in which air is delivered to the upperend of loading cylinder 41 and exhausted from the lower end of saidcylinder to return the loading head 42 to its starting position.

When punch 6' is at the bottom of its working stroke, valve Hi] isautomatically opened by the previously mentioned distance trip means sothat pilot pressure is supplied through pilot lines I09, Ill and H2 toshift valve to a position in which air is supplied to the lower end ofcylinder 92 and exhausted from the upper end of said cylinder. Theresulting upward movement of piston 9i reverses the working valve invalve casing 89 to establish fluid connections through which pressurefluid is routed to and from the press ram to effect an upward returnstroke of cross head 5 and punch 6.

When valve [ID is opened, a shot of air is delivered to the loadingcylinder reversing valve 75 through pilot lines E26 and 88 to ensuredescent of loading head 42 to its starting position. When cross head 5reaches the top of its return stroke, cross head cam 12 opens pilotvalve 59 through which pilot pressure is delivered to shift reversingvalve 62 to a position in which air is exhausted through the lower endof punch-tilting cylinder 32 and is supplied to the upper end of saidcylinder to tilt punch 6 to its inclined workreceiving position.

I claim:

1. In a hydraulic draw press, a crosshead, a punch holder frame securedto said crosshead, a punch holder pivotally supported in said frame byslide bearings permitting limited bodily movement of the punch holdertoward and away from the crosshead, a bearing block and a thrust blockslidably arranged in the punch holder frame between the punch holder andthe crosshead, said bearing block having curved bearing surfacesengaging complementary bearing surfaces of the punch holder and thrustblock between which the bearing block is interposed, the curvature ofthe engaging bearing surfaces of the punch holder, bearing block, andthrust block being such as to provide for self alignment of the punchand punch holder by movement thereof to pathsat right angles to eachother.

2. In a hydraulic draw press, a vertically extended die-holder, adraw-die mounted in the upper end of said die-holder, a verticallymovable crosshead arranged to travel toward and away from said die, atiltable punch pivotally secured to said crosshead for swinging movementfrom a vertical working position in axial alignment with the draw-die toan inclined work-receiving position in which the lower end of the punchis disposed to one side of the draw-die to permit a work piece to beslid upwardly onto said punch, punch-tilting mechanism for swinging saidpunch from it working position to its work-receiving position andvice-versa, means for moving said crosshead toward and away from saiddie, means for operating the punch-tilting mechanism to cause the punchto be disposed in its inclined work-receiving position when said punchis returned to an elevated starting position relative to the draw-die bythe punch carrier after completing a working stroke, power actuatedpunch loading means for sliding a work piece upwardly onto the punchwhen the latter is in its inclined work-receiving position, and meansconnected to and actuated by said last mentioned means for operatingsaid tilting mechanism to swing the punch to its working position afterthe work has been placed thereon and prior to commencement of thedownward or working stroke of the punch and crosshead.

3. A draw press comprising a stationary drawdie provided with a verticalopening for the reception of a work piece, a vertically movable punchadapted to receive thereon a tubular work piece open at one end and toforce the work piece through the opening of the draw-die during theworking stroke of the punch, a vertically movable punch carrier to whichthe upper end of the punch is pivotally secured for swinging movementabout a horizontal axis from a vertical working position in axialalignment with the work-receiving opening of the draw-die to an inclinedloading or work-receiving position and vice versa, operating meansconnected to the punch carrier for raising and lowering same to efiectthe working and return strokes of the punch, a punch tilting mechanismconnected to the punch for swinging the latter from its vertical workingposition to its inclined work-receiving position, means connected to thepunch carrier and to the punch tilting mechanism to operate the latterto swing the punch to its inclined work-receiving position when thecarrier and punch are returned to their starting position following aWorking stroke of the punch, power actuated loading means operable toslide a tubular work piece open at one end upwardly onto the punch whenthe latter is in its inclined workreceiving position and means connectedto said punch tilt ng mechanism and operable by and in response to aloading operation 01' said loading means to operate said punch tiltingmechanism to swing the punch to its working position after the tubularwork piece has been slid onto the punch by said loading means.

4. A fluid actuated draw press comprising a stationary verticallyextending die holder, a draw-die carried by said die holder and providedwith a vertical opening for the reception of a tubular work piece, aninclined work piece guide carried by said die holder and incliningdownwardly and outwardly from the upper end of the die holder, a loadinghead arranged to slide upwardly and downwardly on said guide, a loadinghead operating piston connected to said loading head, a cylinder inwhich said piston works, a reversing valve and pipe connections throughwhich fluid is routed to and from said cylinder to shift the loadinghead from a starting to a punch loading position and vice versa"dependin on the positioning of the reversing valve, a manually operablecontrol valve and pipe connections through which fluid is routed tooperate said reversing valve to a position in which fluid is routed toand from the loading head cylinder to operate the loading head to itspunch loading position, a normally closed loading head pilot valve andpipe connections through which fluid is supplied to operate saidreversing valve to a position in which fluid is routed to and from theloading head cylinder to operate the loading head to its startingposition when said pilot valve is opened, a vertically movable punchadapted to receive thereon a tubular work piece open at one end and toforce the work piece through said die during a downward working strokeof the punch, a vertically movable punch carrier to which: the upper endof the punch is pivotally secured to provide for swinging movement ofthe punch about a horizontal axis from a vertical working position inaxial alignment with the work-receiving opening of the die to aninclined work-receiving position and vice versa, operating meansconnected to the punch carrier for lowering and raising same to effectthe working and return strokes of the punch, a punch tilting mechanismcomprising a cylinder and piston device connected to the carrier and tothe punch for operating the latter from its vertical working position toits inclined work-receiving position and vice versa, a punch tiltingmechanism reversing valve and pipe connections through which fluid isrouted to and from the cylinder and piston device of the punch tiltingmechanism to operate the punch to a working position or to awork-receiving position depending on the positioning of said reversingvalve, a normally closed punch control valve and pipe connectionsthrough which fluid is delivered to operate the reversing valve of thepunch tilting mechanism to a position in which fluid is routed to andfrom the cylinder and piston device of said mechanism to swing the punchto its inclined workreceiving position, valve actuating mechanismcarried by and movable with the punch carrier and arranged toautomatically engage and open said punch control valve when the carrierand punch are returned to startin position following a working stroke ofthe punch, said valve actuating mechanism being also arranged to engageand open the loading head pilot valve when the punch carrier is moved apredetermined distance downwardly from its starting position, thearrangement of the punch and loading head being such that, when thepunch is in its inelined working position, it is in axial alignment withthe working head to permit the tubular work piece to be slid onto thepunch by a load operation of the loading head in response to closure ofthe manually operable control valve through which fluid is supplied tothe loading head operating valve to shift the latter to a loading headoperating position, and a loading head actuated valve and pipeconnections through which fluid is delivered to operate the reversingvalve of the punch tilting mechanism to efiect swinging movement of thepunch from its work-receiving to its working position following thesliding of the work piece onto the punch by the loading head, saidloading head actuated valve being a normally closed valve arranged to beengaged and opened by the loading head as the latter completes itsloading operation.

5. A draw press comprising a stationary drawdie provided with an openingfor the reception of a workpiece, a punch adapted to receive thereon atubular work piece and to force said work piece through said die duringa working stroke of the punch, a reciprocating punch carrier to whichone end of the punch is pivotally secured to provide for swingingmovement of the punch from a working position in axial alignment withsaid die to an inclined work-receiving position and vice versa, andpunch positioning means comprising a cylinder and piston deviceconnected to the punch and to the punch carrier, a reversing valve andfluid circulating conduits connected to said valve and to said cylinderand piston device to providev a, fluid circulating system through whichpressure fluid is routed via the reversing valve to and from thecylinder and piston device to actuate the latter to swing the punch fromits working to its work-receiving position and vice versa dependent onthe position of the reversing valve. 7

6. In a draw press of the type set forth in claim 5 in which thereversing valve is a fluid pressure operated valve, a normally closedpunch control valve and pipe connections through which fluid isdelivered, in the open position of the control valve, to operate saidreversing valve to a position in which fluid is routed to and from saidcylinder and piston device to swing the punch to its inclined workingposition, valve actuating means connected to the punch carrier to traveltherewith and arranged to engage and open said punch control valve whenthe carrier and punch are returned to starting position following aworking stroke of the punch, power actuated loading means including areciprocating loading head arranged to support thereon a tubular workpiece open at one end and operable, during the working stroke thereof,to slide the work piece upwardly onto the punch when the latter is inits inclined work-receiving position, a second normally closed punchcontrol valve arranged to be engaged and opened by the loading headduring the working stroke of the latter and pipe connections throughwhich pressure fluid is routed to said reversing valve via said secondcontrol valve in the open position of the latter to operate thereversing valve to a position in which fluid is routed to and from saidcylinder and piston device to swing the punch to its working positionfollowing the sliding of the work piece onto the punch by the loadinghead.

WILLIAM P. MUIR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,582,217 Henry Apr. 27, 19261,981,490 Witte Nov. 20,1934 2,001,902 Englebertz May 21, 1935 2,023,879Friden Dec. 10, 1935 2,125,249 Temple July 26, 1938 2,161,752 TempleJune 6, 1939 2,339,019 Le Tourneau Jan. 11, 1944 2,403,183 Lefere July2, 1946

